tessellate signed number into positive range

//Tessellate negative or positive value into range: 0-4.
var xNum = 5; //means that we will modulate between 0 to 4.
var outp:int;
for (var i:int = -10; i<10; i++){
 outp = i % xNum;
 if(outp<0){outp = xNum + outp;}
 trace("["+i+"] --->" + outp );
}